12. Anti Arrhythimic Drug Class 2-4 Flashcards
What are the effects of class II AADs?
Inhibit b-mediated increase in HR, contractile force and conduction velocity
- decrease automaticity of SA node
- decrease intracellular Ca overload
- decrease conduction velocity of AV node, his/perkinje system, and ventricles
What are AAD class II primarily used for?
Protect ventricles from Supraventricular arrhythmias and junctional tachycardia
What are some adverse effects of ADD class II?
- Reduce myocardial contractility
- bradycardia
- tachycardia and angina upon sudden withdrawal
- bronchospasms
What are the contraindications of AAD class II?
Cardiogenic shock, 2nd and 3rd degree AV node block, sinus bradycardia, asthma
Can AAD class II be used to convert pts to NSR?
No, just a rate controlling medication, not used to convert pts to NSR
What is the use of type III AADs?
Prolong the refractory period by prolonging action potential, decreases the slop of phase 3 primarily
What are the effects of class III AADs?
- Prolong duration of AP
- Prolong refractory period
- Block K channels
What AAD does amiodarone belong to?
Amiodarone is a class III AAD
What are amiodarone’s effects?
- Block Na channels with fast T(recovery) - ectopic pacemakers
- block Ca channels
- noncompetative antagonist of alpha and beta AR receptors
What is amiodarone most commonly used for?
For atrial and ventricular arrhythmia conversion and maintenance of NSR
What are some problems w/ amiodarone?
- Long half life, >50 days
- CYP inhibitor: 3A4, 2D6, 2C9
- Lots of monitoring! Done every 6 months
Class is dofetilide in?
AAD class III
What are the effects of dofetilide?
- selective for I(kr) K channel
- increase AP duration in atria and ventricles
- no effect on conduction velocity or SA function
What is dofetilide used for? What is it an alternative to?
An alternative to amiodarone, used for atrial fibrillation and flutter conversion and maintenance of NSR
What are the contraindications of dofetilide?
QTc>440ms, CrCl
What kind of monitoring needs to be done on dofetilide?
- electrolytes (Mg, K) - every 3-6 months
- EKG, NSR continuous for 72 hrs - then every 3 months
- renal function - every 3 months
What class dose sotalol belong to?
AAD class III
What are the effects of sotalol?
- Nonselective b-AR antagonist
- Decrease conduction velocity in AV node
- Decrease automaticity of AV node
- Prolong AV node refractory period
What is the safest antiarrhythmic in pregnancy?
Sotalol
What are the contraindications of sotalol?
CrCl450ms, bronchospasm, HR
What is the black box warning for sotalol?
Initiate inpatient d/t QTc prolongation
What should be monitored for sotalol?
HR, EKG, electrolytes, renal funciton
What class does ibutilide belong to?
AAD class III
What is ibutilide used for?
Conversion of atrial arrhythmias
What is the black box warning for ibutilide?
Pro-arrhythmic effect may cause QTc prolongation and TdP
What class does drondarone belong to?
AAD class III
What is drondarone indicated for?
Indicated to decrease hospitalizations for Afib in pts w/ NSR w/ a history of Afib
What pts should not be taking drondarone?
Heart Failure pts
What are the main contraindications of drondarone?
QTc>500ms, liver/lung toxicity w/ amiodarone
What drugs are included in AAD class IV? What is their indication?
Verapamil, diltiazem, bepridil. All are non-DHP CCBs
What are the effects of AAD class IV?
- Primarily in the SA/AV node
- Decrease conduction velocity of AV node
- Prolong refractory period in AV node
- blocks Ca channels in vascular smooth muscle
What are the uses for AAD class IV?
- Reentry tachycardias involving AV node
- Reduce ventricular contractile rate during Afib/A flutter
What are some contraindications of AAD class IV?
- 2nd and 3rd degree heart block
- SBP
What is an important drug interaction of AAD class IV?
Use of CCB w/ BB enhances AV node block
What is magnesiums effect as an antiarrhythmic?
Treatment of digoxin-induced arrhythmias, treatment of TdP
What is the use of adenosine in arrhythmias?
- Increases K conductance –> hyperpolarization
- GPCR mediated inhibition of Ca channels
- Used for PSVT, particularly reentry
What is the use of digoxin in arrhythmias?
- for Afib, an adjunct to rate control, primarily for symptom treatment
- Can be used safely in CHF pts
What drugs are part of class II?
Beta blockers, selective and non selective
- Esmolol, metoprolol, atenolol
- propranolol, timolol